There is a pest around at the moment that needs to be shown who’s boss!
It’s the box tree moth caterpillar, and I was slightly annoyed that two presenters of the recent TV Chelsea coverage said that there’s no answer. If you have any box plants in your garden, you may wish to read this before digging them all up.
The box tree moth caterpillar is quite striking looking with green and yellow stripes from head to tail, with black dots on either side.
It has a voracious appetite, and left to its own devices, this caterpillar will completely defoliate your expensive box plants at great speed.
The moth is also quite pretty – mainly white with iridescent brown bands on each of its wings, although in some cases these can be completely brown. It has a wing span of around 4cm. In winter, small caterpillars hibernate in an envelope of two box leaves that have been spun together the previous autumn.
It’s a relatively new insect to Britain. Whilst the adult moth was first reported in the UK in 2008, caterpillars were not found in private gardens until 2011, and it has since become widespread in London and surrounding areas.
The damage that the caterpillar causes is often mistaken for the fungal infection box blight – but if you look closely and find any cobwebs or leaves that appear to be stuck together, then you need to act fast.
First of all get your hands on a product such as Bug Clear Ultra or Westland Resolva Bug Killer and spray thoroughly and forcefully every 14 days or so
(not just on the outside of the plant, but part the branches and reach inside).
Then remove the damaged foliage, keep the plants well fed and watered and keep spraying every 14 days.
Little is known about this insect, and it’s thought that there are up to three generations a year. So knocking off the first onslaught doesn’t mean that you can put your feet up for the rest of the year. I’m afraid that the combined active period of these munchers is from April to October.
There is a way to be ahead of the game, to prevent the moths from laying eggs in the first place. It’s a pheromone trap which provides season-long biological control; it captures the moths, therefore breaking the life cycle, allowing the box tree to flourish. The contents of the pheromone trap will last for three months, at which time you can re-charge the unit. One trap is effective for around 180 sq m –
Controlling this pest is possible although it requires vigilance on your part. Better that than giving up all those expensive plants without a fight!
© 2018 Valerie McBride Munro